We are conducting a coordinated program of behavioral, neurophysiological, neuroanatomical and biochemical research on the sensory and neuroendocrine basis of olfactory discrimination in mammals. The focus of attention is upon pheromone-like odors that are produced by mammals and that influence ethologically significant behavior patterns such as reproduction, territoriality and social dominance, and upon the neuroendocrine mechanisms underlying such behaviors. The objectives of the research include (1) chemical identification of naturally-occurring odors, (2) study of the mechanisms by which these odors affect endocrine secretions, social behavior and sexual development, (3) analysis of the odors' effects upon the activity of single neurons in the olfactory and limbic-hypothalamic systems, (4) specification of the anatomical connections among structures of the olfactory and limbic-hypothalamic systems, and (5) examination of the functional significance of reciprocal connections among these forebrain structures. It is hoped that our broad, multidisciplinary approach will shed light upon (a) the interrelationships among body odors, olfactory single neuron activity and neuroendocrine control mechanisms, and (b) the morphological and functional connections among brain structures involved in such critical behavioral activities as reproduction and socialization.